Hello Technetters: I've gone from the WS6536 100% world to IPC's 50% hole fill requirement. Unfortunately, I have a .150" thick pcb (G10, with many layers of ground) that must be waved in a selective soldering fixture, that is averaging about 33-50% hole fill. The customer is looking at the 50% hole fill spec, and touching up to meet this requirement (also, they are touching up from the topside and cosmetically getting 100% hole fill to make them feel happy). To achieve the current hole fill, my topside temperature leaving the preheaters is 270F and the bottom-side portions of the board that are exposed to the preheaters and wave are at 320F (my normal range and that recommended by the OA flux manufacturer is 180-220F topside). Also, the speed is 60cm/min (2 f/m), which on my machine equals about a 3 second dwell @ 482F. I can get 50% hole fill if I max out my preheaters which gives me a top-side temp of 320F and bottom-side temp of 370F. Running a board at these temperatures just to meet a 50% hole fill requirement doesn't make sense. My theory: if 50% of a .060" thick board (.030") is OK, then a 25% hole fill of a .150" thick board (.0375") would also be OK. Any thoughts??? Al Kreplick Sr. Mfg. Eng. Teradyne, Inc. 978-370-1726 ############################################################## TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c ############################################################## To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TECHNET <your full name> To unsubscribe: SIGNOFF TECHNET ############################################################## Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information. If you need assistance - contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ##############################################################